This late stage trial will fully test if simvastatin can slow progression. It will involve 1,180 people with secondary progressive MS. It began in March 2017 and will take six years to complete. Recruitment is now open across the UK.

The trial involved 140 people with secondary progressive MS and compared two doses of simvastatin with a placebo (dummy) drug. Researchers found that people taking high dose simvastatin had
reduced brain atrophy (shrinkage)
better end of study disability scores compared with those taking placebo.

In that phase 2 trial simvastatin was generally well tolerated and no one reported any major side effects. The phase 3 trial will now monitor the safety of simvastatin in a much larger number of people with MS.

General side effects

Simvastatin has been used to treat high cholesterol for many years. Commonly reported side effects include: dizziness, fainting, nosebleeds, joint or muscle pain, headache, nausea and digestive problems.

High dose simvastatin

In June 2011 the Food and Drug Administration, which is the US drugs regulator, issued new safety recommendations for simvastatin.

It said that muscle injury (or myopathy) is a risk associated with the 80mg/day higher dose, which will be used in MS-STAT2.